Fabric needling for achieving roughening of one or both sides of a previously made flat textile fabric is known. For example, the article entitled Needling Furnishing Fabrics and Woven Fabric-Reinforced Textiles by Jürgen M. Strössner and Gustav Wizemann (ITB International Textile Bulletin, February 2003) deals with the roughening of fabrics by means of special needles for the gentle handling of fabrics. The needles have an oval, tear-shaped cross section and a longitudinally extending edge which is provided at a flank and which has one or more teeth for roughening the fabric. The dimension (gauge) of the needles is given as 38/40 which corresponds to a height or width of the cross section of the working part in excess of 0.4 mm.
Further, the above-noted article mentions needles having a triangular cross section of the working part for producing velour structures.
Also, for example, DE-OS 1 760 440 describes needles for felting purposes (so-called felting needles) which have a straight shank provided with a working part. The working part has, for example, a triangular or quadrilateral cross section, thus defining three or four lengthwise extending edges. Into the edges teeth are pressed which serve to felt with one another the fibers contained in the random-fiber product, to thus densify the product as the needles penetrate the random-fiber material. The barbs formed at the edges are staggered with respect to one another in the radial direction. They are relatively deep and have a portion which projects beyond the cross section of the shank. As a result, the barbs have a high felting efficiency. Such needles, however, are only poorly adapted, if at all, for the after-treatment of flat textile products, such as woven fabrics. They cause an excessive damage to the woven fabric and are thus overall unfit for this purpose.
DE-OS 25 18 066 describes a further felting needle serving to loop to one another individual fibers of a loose non-woven fabric by multiple needle penetration perpendicularly to the plane of the fabric for densifying the material. The main consideration in this connection is the fiber-entraining capacity which should be as high as possible. Also, the fibers, that is, the individual filaments should be damaged as little as possible. In at least one embodiment, the needle has a triangular cross section and is provided with barbs at the edges. The barbs are staggered with respect to one another. The barbs are of various embodiments: there are those which project beyond the outer contour of the of the working part, as well as those which do not.
DE 195 21 796 C1 too, describes a felting needle for needling a non-woven fiber fabric onto a carrier fabric. By means of needling, the non-woven fiber fabric is attached to the carrier fabric. The needle has a triangular cross section which is bounded by three longitudinally extending, flattened edges. The edges are provided with axially mutually staggered barbs which do not project beyond the outer contour and which have a depth of 0.01 to 0.04 mm, preferably 0.02 mm.
During penetration of a felting needle into a pre-reinforced non-woven material, in a felt or in a carrier fabric, significant longitudinal stresses on the felting needle may be generated. The slimmer the felting needle, the more critical the longitudinal stresses. For the after-treatment of textile material, for example, for roughening, however, as a rule particularly fine needles of a very small cross section should be used. Because of the slender construction of the working part of such a needle, a certain flexibility thereof has to be taken into account. Also, upon penetration of the needles into the fabric, a certain lateral excursion of the needles is to be expected. It is a desideratum that such excursions do not occur in an uncontrolled manner. Needle breakages are particularly disadvantageous. Broken-off working parts impermissibly damage the fabric. Therefore, conventional slender needles cannot be readily made even slimmer.